Before it was discovered 238P came to perihelion on 2005 July 27.[3] When it was discovered on 2005 October 24, it showed vigorous cometary activity until 2005 December 27.[4]Outgassing likely began at least 2 months before discovery.[4] The activity of 238P is much stronger than 133P/Elst-Pizarro and 176P/LINEAR.[4] This may indicate that the impact assumed to have triggered 238P's activity occurred very recently.[4]

Observations of 238P when it was inactive in 2007 suggests that it has a small nucleus only about 0.6 km in diameter.[4]

It last came to perihelion on 2011 March 10,[4] and will next come to perihelion on 2016 October 22.[5][6]